Digital Cameras - Minolta Dimage Xg Test Images

I've begun including links in our reviews to a Thumber-generated
index page for the test shots. The Thumber data includes a host of information
on the images, including shutter speed, ISOsetting, compression setting,
etc. Rather than clutter the page below with *all*that detail, we're posting
the Thumber index so only those interested inthe information need wade through
it!

Moderately high resolution with good detail. Contrast is high, but
color is very good.

The extreme tonal range of this image makes it a tough shot for many
digicams, which is precisely why I set it up this way, and why I shoot
it with no fill flash or reflector to open the shadows. The object is
to hold both highlight and shadow detail without producing a "flat"
picture with muddy colors, and the Dimage Xg performed fairly well, considering
its point-and-shoot design, but contrast was rather high.

The shot at right was taken with a +0.3
EV exposure compensation adjustment, which left the midtones and shadows
very dark, while still blowing out the highlights somewhat. The shot taken
at +0.7 EV looked too bright overall, as the
Dimage Xg seems to take fairly large jumps in exposure despite its 0.3
EV exposure compensation step size. Thus, I chose the shot with the less
blown-out highlights, despite the darker midtones. The Auto
white balance setting produced the best color here, as the Daylight
setting had a pink cast.

Skin tones are quite good, just about what I'd call perfect, and the
blue flowers in the bouquet are just about perfect as well. (Many digicams
have trouble with this blue, but the Dimage Xg renders them pretty accurately.)
Overall color throughout the frame is very good, and saturation is about
right. Resolution is moderately high for a compact three megapixel camera,
but details are just somewhat soft, most likely due in part to anti-noise
processing. Shadow detail is moderate, and noise is low.

To view the entire exposure series from zero to +1.0 EV, see files XGOUTAP0.HTM
through XGOUTAP3.HTM on the thumbnail index page.

Like the wider shot above, this close-up portrait
required an overly-bright exposure to get good midtones. The shot at right
was taken with a +0.7 EV exposure compensation adjustment, one step more
than I used in the wider shot above. The highlights here are quite blown
out, but the shot at +0.3 EV was just too
dark to be considered acceptable. The Dimage Xg's 3x zoom lens helps prevent
strong distortion of Marti's features. Detail and resolution are both
stronger here, with sharp details in Marti's face and hair. Shadow detail
is somewhat limited, and noise is moderately low.

To view the entire exposure series from -0.3 to +1.0 EV, see files XGOUTFACM1.HTM
through XGOUTFACP3.HTM on the thumbnail index page.

Unlike the outdoor portraits, I chose a slightly underexposed shot for
this indoor portrait. The Dimage Xg's built-in flash illuminated the subject
well with a +0.7 EV boost in the exposure. (The
default exposure setting was quite dim. The
shot at right is exposed a bit more than I'd normally like, but the shot
at +0.3 EV still seemed a little dark to me.)
Overall color is very good, with only a slight orange cast from the incandescent
room lighting (mainly noticeable on Marti's hair and shoulder). The blue
flowers in the bouquet are just about right too.

Nearly accurate color with the Incandescent white balance setting,
and good exposure as well.

This shot is always a very tough test of a camera's white balance capability,
given the strong, yellowish color cast of the household incandescent bulbs
used for the lighting. The Dimage Xg's Auto white
balance responded with a pink color cast, while the Incandescent
setting produced a more yellow image. I chose it for the main shot. Despite
the slight yellow cast, color is pretty good throughout the frame, with
good skin tones. (Actually, I somewhat like the gentle yellow cast her,
as it evokes the mood of the original lighting.) The blue flowers are
dark and purplish, but still good considering the difficult light source.
The main shot was taken with a +1.0 EV exposure compensation adjustment,
about average for this subject.

ISO Series:
At the Dimage Xg's ISO 50 and 100 settings, noise is fairly low, even
in the dark shadows. However, noise level increases significantly at ISO
200, and becomes quite distracting at ISO 400, obscuring detail and shifting
color. At ISO 200, I'd say the images are rough but acceptable, but I
wouldn't plan on using the camera at ISO 400 for anything you really cared
about.

The Dimage Xg's Auto white balance setting produced
good color here, with the most accurate white value on the house trim,
but both it and the Daylight setting left a somewhat
warm cast. Resolution is high, and the tree limbs and front shrubbery
show pretty good detail. Details are somewhat soft throughout the frame,
with increased softness in the furthest corners, but the loss of sharpness
in the corners doesn't seem as pronounced as it was with some earlier
DiMAGE X models.

Moderately high resolution and detail with good color, but a slight
overexposure and limited dynamic range.

This image is shot at infinity to test far-field
lens performance. NOTE that this image cannot be directly compared to
the other "house" shot, which is a poster, shot in the studio.
The rendering of detail in the poster will be very different than in this
shot, and color values (and even the presence or absence of leaves on
the trees!) will vary in this subject as the seasons progress. In general
though, you can evaluate detail in the bricks, shingles and window detail,
and in the tree branches against the sky. Compression artifacts are most
likely to show in the trim along the edge of the roof, in the bricks,
or in the relatively "flat" areas in the windows.

This is my ultimate "resolution shot,"
given the infinite range of detail in a natural scene like this. The Dimage
Xg performs well, and captures good detail in the tree limbs over the
roof, the fine foliage in front of the house, and the details of the house
front. Details are a little softer than I'd like for a 3 megapixel camera,
but not bad for a subcompact mode. The corners of the frame are a little
soft, but not as much as was the case with previous "X" models.
The camera's somewhat high native contrast causes it to lose most of the
detail in the bright white paint of the trim on the bay window, and detail
likewise is only moderate in the shadow area above the front door, further
evidence of a limited dynamic range. Overall color is very good though,
with accurate hue and good saturation. The table below shows a standard
resolution and quality series, followed by ISO and effects series.

I routinely shoot this series of images to show the field of view for
each camera, with the lens at full wide angle, at maximum telephoto (3x,
in this case), and at full telephoto with the digital zoom enabled. The
Dimage Xg's lens is equivalent to a 37-115mm zoom on a 35mm camera. That
corresponds to a moderate wide angle to a moderate telephoto, very slightly
biased toward the telephoto end relative to the 35-105mm range that seems
to be standard for most 3x zoom digicams. Following are the results at
each zoom setting.

This shot is often a tough test for digicams, as the abundance of blue
in the composition frequently tricks white balance systems into producing
a warm color balance. The Dimage Xg's Auto white
balance setting fell victim here, and produced a very warm color cast.
The Daylight setting also had a little trouble,
producing a red color cast, but the overall results with it were more
appealing than with the Auto setting. The reddish color cast throws off
the models' skin tones, and turns the blue background a deep purple. Additionally,
the deep shadow areas of the blue robe are purplish. Resolution is high,
and detail is good in the embroidery of the blue robe, as well as in the
instrument strings, and beaded necklaces.

A surprisingly small macro area with good detail, though the flash
has trouble.

The Dimage Xg did very well in the macro category, capturing a minimum
area of only 1.90 x 1.43 inches (48 x 36 millimeters). Resolution is high,
and detail is strong in the dollar bill, coins, and brooch. Details are
slightly sharper in the coins and brooch, however. The left corners are
quite soft, with the softness actually extending down the left side of
the frame. Exposure is good, though overall color is slightly warm. The
Dimage Xg's flash had some trouble throttling
down for the macro area and overexposed the shot, so plan on using external
illumination for macro shots with the Xg.

The Dimage Xg's Auto white balance setting
did the best job here, with nearly accurate overall color. (The Daylight
setting resulted in a very warm cast.) Exposure is about right as well,
and the Dimage Xg distinguishes the subtle tonal variations of the Q60
target without trouble. Colors are vibrant and well-saturated in the large
color blocks, with near accuracy. Detail is low in the shadow area of
the charcoal briquettes, with low image noise.

Slightly limited low-light performance. Autofocus system has trouble,
and noise is slightly high, even with Noise Reduction enabled. Quite adequate
for average city night scenes though.

The Dimage Xg offers fully automatic exposure control only, though with
an adjustable ISO setting. With a maximum shutter time of four seconds,
the Dimage Xg produced bright images only down to the 1/8 foot-candle
(1.3 lux) light level of my test with the ISO 400 setting. (Results were
slightly dim but still usable at the 1/16 foot-candle, 0.67 lux, light
level, which is the darkest of this test.) At ISOs 100 and 200, results
were bright as low as 1/4 foot-candle (2.7 lux), and at ISO 50, results
were bright only as low as 1/2 foot-candle (5.5 lux). Still, overall color
was pretty good, though a hint warm at the dimmer settings, and the Xg's
capabilities are well matched to typical city night scenes, which generally
have lighting in the range of one foot-candle. The Dimage Xg's autofocus
system had trouble in the low lighting, resulting in slightly soft images.
The optional Noise Reduction system reduces some of the image noise, but
not to a great extent. (Here are sample images at the 50,
100, 200,
and 400 ISO settings, without Noise Reduction.)
The table below shows the best exposure I was able to obtain for each
of a range of illumination levels. Images in this table (like all sample
photos) are untouched, exactly as they came from the camera.

(Note: If you'd like to use a light meter
to check light levels for subjects you might be interested in shooting,
a light level of one foot-candle corresponds to a normal exposure of
two seconds at F/2.8 and ISO 100.)

1fc
11lux

1/2fc
5.5lux

1/4fc
2.7lux

1/8fc
1.3lux

1/16fc
0.67lx

1/16fc
(No NR)

ISO
50

4 sec
f2.8

4 sec
f2.8

4 sec
f2.8

4 sec
f2.8

4 sec
f2.8

4 sec
f2.8

ISO
100

2 sec
f2.8

3 sec
f2.8

4 sec
f2.8

4 sec
f2.8

4 sec
f2.8

4 sec
f2.8

ISO
200

1 sec
f2.8

1.5 sec
f2.8

4 sec
f2.8

4 sec
f2.8

4 sec
f2.8

4 sec
f2.8

ISO
400

1/2 sec
f2.8

1 sec
f2.8

2 sec
f2.8

4 sec
f2.8

4 sec
f2.8

4 sec
f2.8

Flash Range Test

A rather underpowered flash at ISO 50.

In my testing, the Dimage Xg's flash showed the limited power typical
of subcompact digicam models. Flash power was brightest at the eight-foot
distance, and steadily decreased in brightness from there. You could get
better range by boosting the ISO (or by using the camera with its ISO
set to the Auto setting), but at the cost of higher image noise. Below
is the flash range series, with distances from eight to 14 feet from the
target.

Average resolution, 1,100 lines of "strong detail." High
barrel and pincushion distortion, however.

The Dimage Xg performed about average for its 3-megapixel class on the
"laboratory" resolution test chart. It started showing artifacts
in the test patterns at resolutions as low as 600~700 lines per picture
height, in both horizontal and vertical directions. I found "strong
detail" out to 1,100 lines vertically, perhaps 1,150 horizontally.
"Extinction" of the target patterns didn't occur until about
1,300 lines.

Optical distortion on the Dimage Xg is a little higher than average at
the wide-angle end, where I measured approximately 0.9 percent barrel
distortion. The telephoto end fared only a little better, as I measured
a 0.5 percent pincushion distortion. (Most 3x-zoom digicams have around
0.8 percent barrel (still too much IMHO) at wide angle, but 0.3 percent
or less pincushion at telephoto.) There's about six or seven pixels of
coloration on either side of the target lines, but it's fairly faint,
indicating only moderate chromatic aberration. (This distortion is visible
as a very slight colored fringe around the objects at the edges of the
field of view on the resolution target.)

A very tight optical viewfinder, though the LCD monitor is nearly
perfect.

The Dimage Xg's optical viewfinder is very tight, showing only
75 percent frame accuracy at wide angle, and about 72 percent at telephoto.
The LCD monitor fared much better, showing approximately 98 percent
accuracy at wide angle, and about 99 percent at telephoto. Given that
I like LCD monitors to be as close to 100 percent accuracy as possible,
the Dimage Xg's LCD monitor does very well, but I'd really like
to see a more accurate optical viewfinder. Flash distribution is pretty
good at wide angle, with just a little falloff at the corners and edges
of the frame. At telephoto, flash distribution is even more uniform.